Electrophotographic photoreceptor, undercoat layer coating liquid therefor, and image forming apparatus and process cartridge using the photoreceptor

Abstract

An electrophotographic photoreceptor, including an electroconductive substrate; an undercoat layer located overlying the electroconductive substrate; and a photosensitive layer located overlying the undercoat layer, wherein the undercoat layer comprises a blocked isocyanate compound and a basic amine.

1. An electrophotographic photoreceptor,
 comprising: 
 an electroconductive substrate; 
 an undercoat layer located overlying the electroconductive substrate; and 
 a photosensitive layer located overlying the undercoat layer, 
 wherein the undercoat layer comprises a crosslinked reaction product of a blocked isocyanate compound, 
 an oil-free alkyd resin including a hydroxyl group, and 
 a basic amine; and 
 the amount of basic amine is from 0.0001 to 5% by weight based on total weight of the oil-free alkyd resin and blocked isocyanate compound; 
 wherein the basic amine is one selected from the group consisting of ammonia, monoethanol amine, diethanol amine, triethanol amine, diethyl ethanolamine, methyl ethanolamine, ethylene diamine, diamino butane, diamino propane, hexane diamine dodecane diamine, diethylene triamine, triethylene tetramine and polyether diamine. 
 
     
     
       2. The electrophotographic photoreceptor of  claim 1 , wherein the electroconductive substrate comprises a material having a volume resistance not greater than 10 10 Ω·cm. 
     
     
       3. The electrophotographic photoreceptor of  claim 1 , wherein the oil-free alkyd resin including a hydroxyl group is a saturated polyester resin formed of direct ester bonds of a polybasic acid and a polyalcohol, with no fatty acid. 
     
     
       4. The electrophotographic photoreceptor of  claim 3 , wherein the oil-free alkyd resin including a hydroxyl group has a hydroxyl value not less than 60 and not greater than 150. 
     
     
       5. The electrophotographic photoreceptor of  claim 1 , wherein the basic amine is diethyl ethanolamine or methyl ethanolamine. 
     
     
       6. The electrophotographic photoreceptor of  claim 1 , wherein the amount of basic amine is 0.01 to 1% by weight. 
     
     
       7. The electrophotographic photoreceptor of  claim 1 , wherein a number of moles of hydroxyl groups of the oil-free alkyd resin including a hydroxyl group is equal to the number of moles of isocyanate groups of the blocked isocyanate resin. 
     
     
       8. An image forming apparatus, comprising:
 the electrophotographic photoreceptor according to  claim 1 ; 
 a charger configured to charge the electrophotographic photoreceptor; 
 an irradiator configured to irradiate the electrophotographic photoreceptor to form an electrostatic latent image thereon; 
 an image developer configured to develop the electrostatic latent image with a toner to form a toner image thereon; 
 a transferer configured to transfer the toner image onto a receiving material; 
 a fixer configured to fix the toner image on the receiving material; 
 a cleaner configured to remove the toner remaining on the electrophotographic photoreceptor after transferred; and 
 a discharger configured to discharge the electrophotographic photoreceptor. 
 
     
     
       9. A process cartridge, comprising:
 the electrophotographic photoreceptor according to  claim 1 ; and 
 at least one selected from the group consisting of a charger, an irradiator, an image developer, a transferer and a fixer.